Systems and methods for robotic surgery are disclosed. In one embodiment, a system comprises a controller configured to control actuation of at least one servo motor； a surgical instrument configured to be movable in a workspace controlled, at least in part, by actuation of the at least one servo motor； and a mechanical tracker linkage coupled between the elongate instrument and a portion of skeletal anatomy of a patient, the tracker linkage comprising one or more joints associated with one or more joint rotation sensors and being configured to send joint signals to the controller； wherein the controller controls positioning of the instrument based at least in part upon the joint signals received from the mechanical tracker.
